A HetNet (heterogeneous network) is a network that is jointly formed by a macro cell with a large coverage area and a micro cell (Small Cell) with a small coverage area. A coverage area of a cell is determined by downlink transmit power of the cell.
In the HetNet, uplink transmit power of a UE (user equipment) depends only on the UE itself; however, downlink transmit power of the macro cell is greater than downlink transmit power of the micro cell. Therefore, an uplink power balance point is different from a downlink power balance point. Referring to FIG. 1, FIG. 1 shows a schematic structural diagram of a macro cell and a micro cell in HetNet networking. A point A in the figure is an uplink power balance point between the macro cell and the micro cell. In this case, a path loss of an uplink signal sent by the UE to the macro cell is the same as that to the micro cell. A point B in the figure, closer to the micro cell, is a downlink power balance point between the macro cell and the micro cell. In this case, signal strength of a downlink signal received by the UE from the macro cell is the same as that from the micro cell. Generally, the point B is also a serving cell handover point. On the right side of the point B, a serving cell of the UE is the micro cell, and on the left side of the point B, the serving cell of the UE is the macro cell. Around the point B is an SHO (Soft Handover) area CD. After the UE enters the SHO area CD, both the macro cell and the micro cell are generally added by an RNC to an active set of the UE. In this case, the UE receives power control instructions from both the macro cell and the micro cell. An existing power control method includes:
responding, by the UE, with a power decreasing operation if the UE receives a “power decreasing” instruction from any cell in the active set; and
responding, by the UE, with a power increasing operation only if the UE receives “power increasing” instructions from all cells in the active set.
In a process of implementing the present invention, the prior art has the following disadvantages: when the UE is located in a CB area, the macro cell is the serving cell of the UE; however, when the macro cell sends a “power increasing” instruction to the UE, the micro cell usually sends a “power decreasing” instruction to the UE; as a result, power control performed by the macro cell on the UE cannot meet an actual uplink transmit power requirement of the macro cell for the UE, and therefore, the UE cannot normally feed back, to the macro cell, a signal indicating whether data is correctly received, thereby affecting normal data transmission.